Java Code Examples for com.puppycrawl.tools.checkstyle.api.DetailAST#getFirstChild()

/**
 * This method extracts all method definitions from the given class (or interface).
 *
 * @param ast
 *            The class (or interface).
 *
 * @return A collection of available methods.
 */
public static Collection<DetailAST> getMethodsFromClass(final DetailAST ast) {
	final Collection<DetailAST> result = new ArrayList<DetailAST>();

	final DetailAST objBlock = ast.findFirstToken(TokenTypes.OBJBLOCK);

	DetailAST child = objBlock.getFirstChild();
	while (child != null) {
		if (child.getType() == TokenTypes.METHOD_DEF) {
			result.add(child);
		}
		child = child.getNextSibling();
	}

	return result;
}
 

/**
 * This method finds out whether the given class is an analysis component or
 * not (by searching for annotations with the names "Plugin" or
 * "Repository").
 *
 * @param clazz
 *            The class in question.
 *
 * @return true if and only if the class is an analysis component.
 */
private static boolean isAnalysisComponent(final DetailAST clazz) {
	// Get the list of modifiers as the annotations are within those
	final DetailAST modifiers = clazz.findFirstToken(TokenTypes.MODIFIERS);

	DetailAST modifier = modifiers.getFirstChild();

	// Run through the modifiers
	while (modifier != null) {
		// If we find an annotation we check the name
		if ((modifier.getType() == TokenTypes.ANNOTATION) && (modifier.findFirstToken(TokenTypes.IDENT) != null)) {
			final String annotationName = modifier.findFirstToken(TokenTypes.IDENT).getText();
			if (annotationName.equals(PLUGIN_ANNOTATION_NAME)
					|| annotationName.equals(REPOSITORY_ANNOTATION_NAME)) {
				// We found an annotation with the correct name
				return true;
			}
		}

		modifier = modifier.getNextSibling();
	}

	// Seems like there is no such annotation
	return false;
}
 

/**
 * This method finds out whether the given class implements the record factory
 * or not.
 *
 * @param clazz
 *            The class in question.
 *
 * @return true if and only if the class implements the record factory.
 */
private static boolean implementsFactory(final DetailAST clazz) {
	final DetailAST implementsClause = clazz.findFirstToken(TokenTypes.IMPLEMENTS_CLAUSE);
	if (implementsClause != null) {
		DetailAST clause = implementsClause.getFirstChild();

		// Run through the whole implements clause
		while (clause != null) {
			// It has to be a combination of two names
			if ((clause.getType() == TokenTypes.DOT) && (clause.getChildCount() == 2)) {
				final String fstClauseIdent = clause.getFirstChild().getText();
				final String sndClauseIdent = clause.getLastChild().getText();

				return (FACTORY_FST_NAME.equals(fstClauseIdent)) && (FACTORY_SND_NAME.equals(sndClauseIdent));
			}

			clause = clause.getNextSibling();
		}
	}
	return false;
}
 

@Override
public void visitToken(DetailAST ast) {
	DetailAST block = ast.findFirstToken(TokenTypes.OBJBLOCK);
	DetailAST candidate = block.getFirstChild();
	List<DetailAST> methods = new ArrayList<>();
	while (candidate != null) {
		candidate = candidate.getNextSibling();
		if (candidate != null && candidate.getType() == TokenTypes.METHOD_DEF) {
			DetailAST ident = candidate.findFirstToken(TokenTypes.IDENT);
			DetailAST parameters = candidate.findFirstToken(TokenTypes.PARAMETERS);
			if (isOrderedMethod(ident, parameters)) {
				methods.add(ident);
			}
		}
	}
	checkOrder(methods);
}
 

private boolean hasPublicStaticField(DetailAST ast) {
    DetailAST classBody = ast.findFirstToken(TokenTypes.OBJBLOCK);
    DetailAST maybeVariableDefinition = classBody.getFirstChild();

    String className = ast.findFirstToken(TokenTypes.IDENT).getText();

    // Filter out util classes
    if (className.endsWith("Utils")) {
        return false;
    }

    while (maybeVariableDefinition != null) {
        if (maybeVariableDefinition.getType() == TokenTypes.VARIABLE_DEF) {
            DetailAST modifiers = maybeVariableDefinition.findFirstToken(TokenTypes.MODIFIERS);
            if (modifiers != null && isPublic(modifiers) && isStatic(modifiers)) {
                return true;
            }
        }

        maybeVariableDefinition = maybeVariableDefinition.getNextSibling();
    }

    return false;
}
 

/** {@inheritDoc} */
@Override public void visitToken(DetailAST ast) {
    DetailAST node = ast.findFirstToken(MODIFIERS);

    if (node == null)
        node = ast.findFirstToken(ANNOTATIONS);

    if (node == null)
        return;

    for (node = node.getFirstChild(); node != null; node = node.getNextSibling()) {
        if (node.getType() == TokenTypes.ANNOTATION &&
            Override.class.getSimpleName().equals(annotationName(node)) &&
            node.getLineNo() != nextNode(node).getLineNo())
            log(node.getLineNo(), DIFF_LINE_ERR_MSG, annotationName(node));
    }
}
 

private int countDescendantsOfType(DetailAST ast, int... types) {
	int count = 0;
	for (int type : types) {
		count += ast.getChildCount(type);
	}
	DetailAST child = ast.getFirstChild();
	while (child != null) {
		count += countDescendantsOfType(child, types);
		child = child.getNextSibling();
	}
	return count;
}
 

/**
 * This method checks whether the given trees are more or less equal. This is
 * necessary as the available methods do not work as expected for this special
 * case.
 *
 * @param actual
 *            The actual tree.
 * @param expected
 *            The expected tree.
 *
 * @return true if and only if the trees are (more or less) equal.
 */
private static boolean treeCompare(final DetailAST actual, final DetailAST expected) {
	if ((actual != null) && (expected != null) && (actual.getType() == expected.getType())) {
		// If they are identifiers, we check the texts
		if ((actual.getType() == TokenTypes.IDENT) && (!actual.getText().equals(expected.getText()))) {
			return false;
		}

		// Everything fine so far. Check the equality of the children
		DetailAST actChild = actual.getFirstChild();
		DetailAST expChild = expected.getFirstChild();

		while (actChild != null) {
			// The treeCompare method checks whether one of the children is null (we
			// recognize therefore if the parents have different number of children).
			if (!MonitoringRecordFactoryConventionCheck.treeCompare(actChild, expChild)) {
				return false;
			}

			actChild = actChild.getNextSibling();
			expChild = expChild.getNextSibling();
		}

		// Everything seems to be fine - just make sure that expChild is null as well or
		// otherwise the parents had a different number of children
		return expChild == null;
	}

	return false;
}
 

private boolean isSimpleEqualsExpression(DetailAST expression) {
	if (expression == null || expression.getType() != TokenTypes.EQUAL) {
		return false;
	}
	DetailAST child = expression.getFirstChild();
	while (child != null) {
		if (child.getChildCount() > 0) {
			return false;
		}
		child = child.getNextSibling();
	}
	return true;
}
 

private void visitQuestion(DetailAST ast) {
	DetailAST expression = ast.getFirstChild();
	if (!hasType(expression, TokenTypes.LPAREN)) {
		if (expression != null && requiresParens(expression)) {
			log(ast.getLineNo(), ast.getColumnNo(), "ternary.missingParen");
		}
	}
	while (hasType(expression, TokenTypes.LPAREN)) {
		expression = expression.getNextSibling();
	}
	if (isSimpleEqualsExpression(expression) && !isEqualsTestAllowed(ast)) {
		log(ast.getLineNo(), ast.getColumnNo(), "ternary.equalOperator");
	}
}
 

private void visitCatch(DetailAST ast) {
	DetailAST child = ast.getFirstChild();
	while (child != null && child.getType() != TokenTypes.PARAMETER_DEF) {
		child = child.getNextSibling();
	}
	if (child != null) {
		visitParameterDef(child);
	}
}
 

private boolean hasOverrideAnnotation(DetailAST modifiers) {
	DetailAST candidate = modifiers.getFirstChild();
	while (candidate != null) {
		if (candidate.getType() == TokenTypes.ANNOTATION) {
			DetailAST dot = candidate.findFirstToken(TokenTypes.DOT);
			String name = (dot != null ? dot : candidate).findFirstToken(TokenTypes.IDENT).getText();
			if ("Override".equals(name)) {
				return true;
			}
		}
		candidate = candidate.getNextSibling();
	}
	return false;
}
 

/**
 * Checks if a given method is writeObject().
 * @param aAST method def to check
 * @return true if this is a writeObject() definition
 */
private boolean isWriteObject(DetailAST aAST)
{
    // name is writeObject...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"writeObject".equals(ident.getText())) {
        return false;
    }

    // returns void...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.LITERAL_VOID) {
        return false;
    }

    // should have one parameter...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params == null || params.getChildCount() != 1) {
        return false;
    }
    // and paramter's type should be java.io.ObjectOutputStream
    final DetailAST type =
        (DetailAST) ((DetailAST) params.getFirstChild())
            .findFirstToken(TokenTypes.TYPE).getFirstChild();
    final String typeName = FullIdent.createFullIdent(type).getText();
    if (!"java.io.ObjectOutputStream".equals(typeName)
        && !"ObjectOutputStream".equals(typeName))
    {
        return false;
    }

    // and, finally, it should throws java.io.IOException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 1) {
        return false;
    }
    final DetailAST expt = (DetailAST) throwsAST.getFirstChild();
    final String exceptionName = FullIdent.createFullIdent(expt).getText();
    if (!"java.io.IOException".equals(exceptionName)
        && !"IOException".equals(exceptionName))
    {
        return false;
    }

    return true;
}
 

/**
 * Checks if a given method is readObject().
 * @param aAST method def to check
 * @return true if this is a readObject() definition
 */
private boolean isReadObject(DetailAST aAST)
{
    // name is readObject...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"readObject".equals(ident.getText())) {
        return false;
    }

    // returns void...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.LITERAL_VOID) {
        return false;
    }

    // should have one parameter...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params == null || params.getChildCount() != 1) {
        return false;
    }
    // and paramter's type should be java.io.ObjectInputStream
    final DetailAST type =
        (DetailAST) ((DetailAST) params.getFirstChild())
            .findFirstToken(TokenTypes.TYPE).getFirstChild();
    final String typeName = FullIdent.createFullIdent(type).getText();
    if (!"java.io.ObjectInputStream".equals(typeName)
        && !"ObjectInputStream".equals(typeName))
    {
        return false;
    }

    // and, finally, it should throws java.io.IOException
    // and java.lang.ClassNotFoundException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 3) {
        return false;
    }
    final DetailAST excpt1 = (DetailAST) throwsAST.getFirstChild();
    final String exception1 = FullIdent.createFullIdent(excpt1).getText();
    final String exception2 =
        FullIdent.createFullIdent(throwsAST.getLastChild()).getText();
    if (!"java.io.IOException".equals(exception1)
        && !"IOException".equals(exception1)
        && !"java.io.IOException".equals(exception2)
        && !"IOException".equals(exception2)
        || !"java.lang.ClassNotFoundException".equals(exception1)
        && !"ClassNotFoundException".equals(exception1)
        && !"java.lang.ClassNotFoundException".equals(exception2)
        && !"ClassNotFoundException".equals(exception2))
    {
        return false;
    }

    return true;
}
 

/**
 * Checks if a given method is writeReplace() or readResolve().
 * @param aAST method def to check
 * @return true if this is a writeReplace() definition
 */
private boolean isWriteReplaceOrReadResolve(DetailAST aAST)
{
    // name is writeReplace or readResolve...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"writeReplace".equals(ident.getText())
        && !"readResolve".equals(ident.getText()))
    {
        return false;
    }

    // returns Object...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.DOT
        && typeAST.getType() != TokenTypes.IDENT)
    {
        return false;
    }

    // should have no parameters...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params != null && params.getChildCount() != 0) {
        return false;
    }

    // and, finally, it should throws java.io.ObjectStreamException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 1) {
        return false;
    }
    final DetailAST excpt = (DetailAST) throwsAST.getFirstChild();
    final String exception = FullIdent.createFullIdent(excpt).getText();
    if (!"java.io.ObjectStreamException".equals(exception)
        && !"ObjectStreamException".equals(exception))
    {
        return false;
    }

    return true;
}
 

/**
 * Checks if a given method is writeObject().
 * @param aAST method def to check
 * @return true if this is a writeObject() definition
 */
private boolean isWriteObject(DetailAST aAST)
{
    // name is writeObject...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"writeObject".equals(ident.getText())) {
        return false;
    }

    // returns void...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.LITERAL_VOID) {
        return false;
    }

    // should have one parameter...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params == null || params.getChildCount() != 1) {
        return false;
    }
    // and paramter's type should be java.io.ObjectOutputStream
    final DetailAST type =
        (DetailAST) ((DetailAST) params.getFirstChild())
            .findFirstToken(TokenTypes.TYPE).getFirstChild();
    final String typeName = FullIdent.createFullIdent(type).getText();
    if (!"java.io.ObjectOutputStream".equals(typeName)
        && !"ObjectOutputStream".equals(typeName))
    {
        return false;
    }

    // and, finally, it should throws java.io.IOException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 1) {
        return false;
    }
    final DetailAST expt = (DetailAST) throwsAST.getFirstChild();
    final String exceptionName = FullIdent.createFullIdent(expt).getText();
    if (!"java.io.IOException".equals(exceptionName)
        && !"IOException".equals(exceptionName))
    {
        return false;
    }

    return true;
}
 

/**
 * Checks if a given method is readObject().
 * @param aAST method def to check
 * @return true if this is a readObject() definition
 */
private boolean isReadObject(DetailAST aAST)
{
    // name is readObject...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"readObject".equals(ident.getText())) {
        return false;
    }

    // returns void...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.LITERAL_VOID) {
        return false;
    }

    // should have one parameter...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params == null || params.getChildCount() != 1) {
        return false;
    }
    // and paramter's type should be java.io.ObjectInputStream
    final DetailAST type =
        (DetailAST) ((DetailAST) params.getFirstChild())
            .findFirstToken(TokenTypes.TYPE).getFirstChild();
    final String typeName = FullIdent.createFullIdent(type).getText();
    if (!"java.io.ObjectInputStream".equals(typeName)
        && !"ObjectInputStream".equals(typeName))
    {
        return false;
    }

    // and, finally, it should throws java.io.IOException
    // and java.lang.ClassNotFoundException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 3) {
        return false;
    }
    final DetailAST excpt1 = (DetailAST) throwsAST.getFirstChild();
    final String exception1 = FullIdent.createFullIdent(excpt1).getText();
    final String exception2 =
        FullIdent.createFullIdent(throwsAST.getLastChild()).getText();
    if (!"java.io.IOException".equals(exception1)
        && !"IOException".equals(exception1)
        && !"java.io.IOException".equals(exception2)
        && !"IOException".equals(exception2)
        || !"java.lang.ClassNotFoundException".equals(exception1)
        && !"ClassNotFoundException".equals(exception1)
        && !"java.lang.ClassNotFoundException".equals(exception2)
        && !"ClassNotFoundException".equals(exception2))
    {
        return false;
    }

    return true;
}
 

/**
 * Checks if a given method is writeReplace() or readResolve().
 * @param aAST method def to check
 * @return true if this is a writeReplace() definition
 */
private boolean isWriteReplaceOrReadResolve(DetailAST aAST)
{
    // name is writeReplace or readResolve...
    final DetailAST ident = aAST.findFirstToken(TokenTypes.IDENT);
    if (!"writeReplace".equals(ident.getText())
        && !"readResolve".equals(ident.getText()))
    {
        return false;
    }

    // returns Object...
    final DetailAST typeAST =
        (DetailAST) aAST.findFirstToken(TokenTypes.TYPE).getFirstChild();
    if (typeAST.getType() != TokenTypes.DOT
        && typeAST.getType() != TokenTypes.IDENT)
    {
        return false;
    }

    // should have no parameters...
    final DetailAST params = aAST.findFirstToken(TokenTypes.PARAMETERS);
    if (params != null && params.getChildCount() != 0) {
        return false;
    }

    // and, finally, it should throws java.io.ObjectStreamException
    final DetailAST throwsAST =
        aAST.findFirstToken(TokenTypes.LITERAL_THROWS);
    if (throwsAST == null || throwsAST.getChildCount() != 1) {
        return false;
    }
    final DetailAST excpt = (DetailAST) throwsAST.getFirstChild();
    final String exception = FullIdent.createFullIdent(excpt).getText();
    if (!"java.io.ObjectStreamException".equals(exception)
        && !"ObjectStreamException".equals(exception))
    {
        return false;
    }

    return true;
}
 

/**
 * Get the first child of a DetailAST.
 * @param aAST the DetailAST.
 * @return the first child of aAST.
 */
protected DetailAST getFirstChild(DetailAST aAST)
{
    return (DetailAST) aAST.getFirstChild();
}
 

/**
 * Get the first child of a DetailAST.
 * @param aAST the DetailAST.
 * @return the first child of aAST.
 */
protected DetailAST getFirstChild(DetailAST aAST)
{
    return (DetailAST) aAST.getFirstChild();
}